Counterweight control system for lifting device carriages



March 20, 1945. 2,371,865

COUNTERWEIGHT CONTROL SYSTEMS FOR LIFTING DEVICE CARRIAGES P. J-M. T.ALLARD a o T E v N \a ierre Tean-Mqn eTWeodoRN N g rr Y.

Patented Mar. 20, 1945 ooUNTEnWErGH'r ooN'mon srs'rnmg'ron LIFTINGDEVICE OARRIAGES Pierre Jean-Marie Theodore Allard, Chantilly, France;yested in the Alien Property Custodian ApplicationF ebr uary 1, 1943,Serial e. 474,326 In France Marclijll, 1941 Claims. ((1212-84)- Myinvention relates to lifting devices of the type including a horizontalor slightly inclined guideway' along whicha carriage is adapted to run,to which crab is hung an automatic grab or like goods-handling device,said carriage advancing in a given direction under the action of acounterweight adapted to return the carriage towards the dischargingposition- The invention is; more particularly. applicable to theapparatuses of the type described in my prior specification Ser. No.282,817, filed on July 4, 1939, now Patent No.'2,270,91 6, grantedJanuary 27, 1942.

Said invention has for its object a countenweight control systemforreturning the carriage towards the discharging position and adaptedto stop the carriage at a predetermined point of its return travel. Tothis end, according to the invention, an adjustably positioned stop isarranged in the path of the counterweight so as to balancethe action ofthe latter and to stop the carriage at the desiredpoint. a

In the .case of an automatic grab of the type described in the abovementioned prior specifica-' tion, this stopping of the carriage producesat the'sarne moment the automatic emptying of the grab through the slackgiven to the lifting cable to which-the grabis suspended. Other featuresof the invention will: appear from the following description, referencebeing made to .the accompanying drawing in which;

' Fig. 1 is a diagrammatic viewof a first form of the invention.

weight stop, including a single stop adjustably weight It.

arranged in thefsame longitudinal vertical plane as theicable 2. A leverB is pivotally secured as at- 9 to thecarriage 4, said lever beingprovided with a counterweight or aspring 10 for urging brake shoe 36into contact with the rail or guidewayi.

When in position for loading over the axis, AB,

the carriage abuts against the. stop I I under the actionof the weightof the grabsuspended to the cable, 2.

The carriage is urged to .theright in Fig. 1, by thereturn system,including a cable 12 passing over a return pulley l3 and to the end ofwhich is suspended a driving counterweight I 4.

In the forrnof execution of Fig. 1, a rotary rod I5 is arranged parallelto the path of; the counterweight M. Rod 15 is provided at differentheights with fingers l6, l1, l8, which fingers project-radially. atdifierent angles from the rod and serve as stops when moved into thepath of the. counterweight. Rod I5 is mounted in bearings l5a and (5battached toa stationary object.

In the form of execution illustrated inFigsIZ and 2'A, 2I designates oneof the stops distributed at different heights along the path of thecounterv This stop is carried by a lever 22 adapted'to pivot round astationary axis 23 said stop being urged in'one direction by a spring 24and-in the opposite direction by the armature empties its contentsbetween two extreme points corresponding to the extremities of the pathallowed for the adjustable stop.

Referring to the drawing, 1 designatesan automatic grab, secured to theend of a hoisting cable 2 passing over a return pulley 3 carried by acarriage or trolley 4, the rollers 5 of said trolley running along .a.horizontal or slightly inclined rail '5. The opening ring I is suspendedby a cable 25 of a coil 26. Coil 26 is inserted in the circuit of 1 acurrent supply 21, which circuit has a switch 28. Normally, the switch28 being open, the spring'z l urges thelever 2 2'into the position shownin dot and dash lines, for which th stop 2| is no longer in the path ofthecounterweight I4. Whenthe switch 28 is closed,v the coil '25 attractsits armature 25 which, in turn, brings the stop 2! back into the path ofthe counterweight. I

.H'I hestops '21 oscillate back and forth in slots ing rotation of therod, a motor constantly r0- tating the nut, and means controlled by thestop at two points of its travel for reversing the direction of rotationimparted to the nut. l

10.- In a lifting device including a substantially horizontal guideway,a grab, a carriage carrying said grab and adapted to move along theguideway between loading and discharging positions,

a descending counterweight for returning the grab towards thedischarging position, abutment means for stopping said descendingcounterweight, and means for adjustably moving said abutment means alongthe path of the counterweight to different obstructing positions.

PIERRE JEAN-MARIE I THEODORE ALLARD.

